A Prairie Home Companion (PG)

A confession. Several times during Robert Altman's final film, I almost fell asleep.

What would be a bad sign with any other movie is here meant as a compliment. Watching A Prairie Home Companion is like lying in a warm bath on a winter's night. For a little while, all's right with the world, so enjoy.

The real Prairie Home Companion, Garrison Keillor's homespun mix of storytelling and music, is still going strong on American radio after 32 years. In the movie, the show is on its last legs and the network boss (Tommy Lee Jones) is on his way to wield the axe.

Keillor, playing a host called GK, gathers his band of performers, including ageing chanteuses Yolanda and Rhonda (Meryl Streep and Lily Tomlin) and wisecracking cowboys Dusty and Lefty (Woody Harrelson and John C Reilly), for the last show. Watching over proceedings is security chief Guy Noir (Kevin Kline).

Everything is same old, same old, until the arrival of a mysterious woman in white.

This being an Altman and Keillor production, the actors are left to improvise (a crueller soul would say ramble) their way through scenes. At one point, when a heavily pregnant producer gets so exasperated with the yakking Keillor she fakes labour to get him to shut up, Altman seems to be lampooning his own style – or its critics. Some of the cast prove better at the acting-natural lark than others. Streep and Tomlin are disappointing, more like strangers than sisters. Streep makes up for it, though, with a belting singing voice.

Altman's film takes its own sweet time to reach a conclusion of sorts. A fitting way for a director who was always his own man to bow out.

Directors are seldom fortunate enough to realise they are working on their last movie, so we are often left with insubstantial tributes to their craft.

Robert Altman, I suspect, may have known this film would be his last. He was 80, after all, had had a heart transplant, and, just to reinforce the point, on his last three pictures the insurance company had appointed a standby director in case Altman could not finish.

If Altman did know this was to be his last gift to the audience then he has left them with something to admire.The theme of endings and death runs through this film, which is based on the – fictional – final broadcast of Garrison Keillor's popular radio show, even though continues to enjoy rude good health on American public radio.

Check it out on the internet – it is great. It is an ensemble of variety acts, monologues, skits, and comedy turns linked by Keillor's lugubrious anecdotes about Lake Wobegon. Characters drift in and out of the film. Woody Harrelson and John C Reilly are movie-stealing cowboy comedians; Meryl Streep and Lily Tomlin are singing sisters, with Lindsay Lohan as their next generation; and Kevin Kline is a fading acting talent hanging on to his final moments of glory.

The one enigmatic presence in all of this is Virginia Madsen as, perhaps fittingly with hindsight, the Angel of Death, who will be escorting someone from the building tonight. This is a film of small and consistent delights. It is shot through with lovely moments, but the overriding emotion is one of affection between a superb cast and a magnificent director.

There is affection, too, between Altman and the movies. The rage and anger of M.A.S.H. and Nashville and many of his other films is missing here. Instead, he seems finally to have embraced his role as a supreme storyteller.Sit back and be grateful.